Carburetor



Feb. 4, 1936.

E. L. BROWN CARBURETOR Filed Dec. 21, 1955 Zhwentor 81 mm QED mam (Ittornegs Patented Feb. 4, 1936 UNITED PAT T OFFIE 9 Claims.

This invention relates tcrdevices for carbureting gases, ordinarily air, by bubbling the gas through a volatile hydrocarbon, preferably a light gasoline or pentane.

A practical embodiment of the invention is illustrated in the accompanying drawing, in which,-

Fig. l is a view of the complete device, partly in elevation and partly in section.

Fig. 2 is an elevation of the gas injecting nozzle, with a part broken away to show a section.

Referring first to Fig. l, the ground level is indicated at G-G, and 6 is a tank or reservoir, conveniently of cylindrical form, buried in the ground. Projecting through the bottom of the tank 6 is a cylindrical well I, closed at its lower end and open at its upper end within the tank, such open upper end being at least as high as the highest liquid level in the tank. A series of small ports 8 allow liquid hydrocarbon, indicated at H, to flow into well 1. The capacity of these ports is such as to limit the supply of hydrocarbon to the well, as will be later explained.

A pipe 9 extends through the wall of tank 6 and downward through the open upper end of well I. Beneath the ports 8 it carries a nozzle l I (see Fig. 2) closed at its lower end and provided with a plurality of circumferential rows of ports l2. Preferably the outer face of the nozzle is formed with circumferential angular grooves l3, and the ports l2 are drilled angularly (see the sectioned part of Fig. 2) so as to direct discharging gas upward and outward.

The pipe 9 is connected to the discharge of a rotary compressor l4 driven by an electric motor I5. The intake connection l6 of the compressor is connected to a pipe I! which serves as a combined intake and vent, and is open to the atmosphere at l8, where a protecting canopy I9 is provided. The open end I8 is located to minimize the possibility of ignition of vapor which, at times issues from the pipe H.

The pipe I! is connected to the side of a combined filling and vapor venting fitting 2|. This fitting is connected by pipe 22 with the vapor space in tank 6, and has a valve seat 23 which controls communication between pipes l1 and 22. A filling plug 24 is threaded into the filling aperture in the top of fitting 2 I, normally closing the same. This plug 24 carries a valve head 25 which seals on seat 23 when plug 24 is screwed home.

The offtake for carbureted gas, in this case carbureted air, is indicated at 26 and leads from pipe 22 to any point of use, such as a gas stove, water heater or the like (not shown).

The compressor It operates to force air through the nozzle H and thus maintain in the reservoir 6 a supply of carbureted air under pressure. This pressure is automatically controlled by starting and stopping the motor 15 which drives the compressor. The automatic control functions to stop the motor if the pressure in the reservoir 6 rises above a desired maximum and to restart the motor when the pressure falls below this maximum. The automatic control also functions to stop the motor if the pressure in the reservoir 6 falls below a desired minimum. In the latter case the automatic control can not restart the motor but must be manually actuated for this purpose. This latter control is a safety feature, intended to stop the motor permanently if the pressure in the reservoir 6 falls so low that burners fed therefrom might go out. Contingencies which might produce this result are failure of the current to the motor l5, removal of the plug 24, or breakage of the delivery pipe line 26. 7

While the desired result might be produced in various ways, the simplest from a commercial standpoint, is to use two commercial pressure actuated switches with their electrical switch elements connected in series in the motor circuit and their pressure actuated elements both subject to pressure in the reservoir 6.

The main controlling switch is normally closed and opens at the desired maximum pressure. The safety switch is normally open and. closes when the desired minimum pressure is attained. A re-set button is provided to hold it closed manually. until the motor and compressor can build up the desired minimum pressure inreservoir 6.

The pipe 21 leads from the vapor space of the reservoir 6 to two identical pressure motors 28 and 29. The motor 28 operates through a lever and linkage 32 to tilt a switch tube 33 counterclockwise about a fulcrum 34 on rise of pressure. The mechanism is loaded by springs, one of which appears at 35, so that tilting occurs in a counter clockwise direction when pressure exceeds the desired maximum. The motor 29 operates through a lever 35 and linkage 36 to tilt a switch tube 31 about a fulcrum 38 when pressure is above a desired minimum value, such minimum being determined by the stress in certain springs, one of which appears at 39.

The switch tubes 33 and 3'! are reversely arranged and the contacts in the tube 33 are at the right hand end so that they are connected by the drop of mercury 4| when pressure is below the desired maximum. In the tube 31, however,

the contacts are at the left hand end so that they are disconnected by the drop of mercury 42 whenever pressure is below the desired minimum. Obviously, the circuit through switch tube 31 can never be closed automatically, and to permit closure a push button 43 is provided. By pushing this button in, the tube 31 is tilted counterclockwise and may be held thus tilted until the motor operates to build up the necessary minimum pressure in the reservoir 6.

The two pressure actuated switch mechanisms above described are common commercial types and therefore need not be described in detail. They are essentially identical except for their relatively reverse arrangements of the tubes 33 and 31, and except for the fact that they are adjusted to respond at different pressures, as described.

The circuit can be traced as follows: Wire 44 leading from any suitable source of current is connected to one terminal in switch tube 31. From the other terminal a wire 45 leads to one terminal in switch tube 33. From the other terminal of switch tube 33 a wire 46 leads to one terminal of motor IS. The electric line 41 is connected to the second terminal of the motor l5.

Assuming that tank 6 contains suitable hydrocarbon, say pentane, and that plug 24 is screwed home and motor I5 is running, the compressor l4 will draw air through the pipe I! from the open end l8 and discharge it through the nozzle H. This causes violent ebullition in the well I which will cause much of the liquid pentane to fiow over the top of the well. Thereafter the restricting action of ports 8 will limit the supply of liquid pentane to well 1 to a rate which somewhat exceeds the maximum rate at which liquid hydrocarbon is evaporated.

-It should be noted that the capacity of the ports 8 is limited to a rate appropriate to the rate of air supply so that a stable operative condition will soon be reached in which the hydrocarbon liquid bubbling over the top of well 1 balances the excess supplied through ports 8. The effect is to eliminate the disturbing effects which would otherwise result from varying liquid level in well 1, and a consequent varying discharge rate of the compressor N.

If theoperation of the compressor raises the pressure in the reservoir 6 above the desired maximum, the bellows 28 will respond, tilt the tube 33 counterclockwise, and break the motor circuit. Depletion of pressure through outflow of carbureted air through pipe 26 or otherwise, will cause motor 28 to restore the circuit by permitting clockwise tilting of the switch tube 33. If the supply of current to the motor I5 should fail, or if for any other reason the pressure in the reservoir 6 falls below the minimum, determined by the loading of the motor 29, the motor will permit the switch tube 31 to tilt in a clock.- wise direction and interrupt the circuit. To restore the motor l5 to operation it is necessary to push the button 43 inward and hold it until compressor I4 has developed sufiicient pressure in the motor 29 to maintain the tube 31 tilted to its circuit closing position.

To fill the tank 6 it is unnecessary to open the motor circuit manually, though this might be done by any suitable means. All that is strictly necessary is to start unscrewing the filling plug 24. The initial opening movement of the plug connects the pipe 22 with the vent pipe 11. The pressure in the reservoir 6 is quickly dissipated and collapse of the bellows motor 29 interrupts the circuit of the electric motor l5. The vapor vented from the reservoir 6 is discharged at 18 where it can do no harm. This all occurs before the plug 24 can be completely removed. Consequently by the time the plug is completely removed pressure in the reservoir 6 has been dissipated and the motor I5 has been stopped. After the tank has been filled the plug 24 is replaced and screwed home. The system can then be placed in operation by pressing the button 43 and holding it in until the compressor l4 develops the desired minimum pressure in reservoir 6. The operator will be instructed not to press the button 43 until all burners are turned off, and a warning to this effect may be displayed adjacent the button.

While the particular embodiment illustrated has been described in considerable detail, and is preferred, modifications are possible within the scope of the invention.

What is claimed is,'

1. The combination of a closed reservoir adapted to be partially filled with volatile liquid hydrocarbon; means for forcing a gas under pressure through such hydrocarbon and for accumulating under pressure in the reservoir, gas thus carbureted; a filling fitting for the reservoir, said fitting having a filling opening and a vent intermediate the filling opening and said reservoir,-

a vent connection leading from said vent to a said vent, and a position through which it must pass in the process of opening in which it maintains the filling opening closed and connects said vent with said reservoir.

2. The combination defined in claim 1, in which the means for forcing gas under pressure is a motor-driven pump and the intake of said pump is connected to said vent connection.

3. The combination of a closed reservoir adapted to be partially filled with volatile liquid hydrocarbon; means for forcing gas under pressure through such hydrocarbon and for accumulating gas thus carbureted under pressure in the reservoir; a motor for driving such forcing means; pressure actuated means controlling said motor and arranged to stop the same when pressure in said reservoir falls below the desired minimum; a filling fitting for the reservoir, said fitting having a filling opening and a vent intermediate the filling opening and said reservoir, a vent'connection leading from such vent to a discharge point remote from said fitting; and a closure for the filling opening in said fitting, said closure having a position in which it closes the filling opening and isolates said reservoir from said vent, and a position through which it must pass in the process of opening the filling opening in which it maintains the filling opening closed and connects said vent with said reservoir.

4. The combination defined in claim 3, in which the means for forcing gas under pressure has its intake connected with said vent connection.

5. The combination defined in claim 3, in which manual means are provided to shift said pressure actuated means from its motor stopping position irrespective of the pressure in said reservoir.

6. The combination of a closed reservoir adapted to be partially filled with volatile liquid hydrocarbon; means for forcing gas under pressure through such hydrocarbon and for accumulating gas thus carbureted under pressure in the reservoir; an electric motor for driving such forcing means; two independent pressure actuated switches, each subject to the pressure in said reservoir, said switches being arranged to control the flow of current to said motor in such a way that the opening of either switch will stop the motor, one of said switches being normally closed and arranged to open when pressure in said reservoir exceeds a desired maximum, and the other of said switches being normally open and arranged to close when pressure in said reservoir is above a desired minimum; and manually operable means for closing the circuit controlled by said normally open switch.

7. In a carburetor, the combination of a closed reservoir adapted to be partially filled with volatile liquid hydrocarbon and having an ofitake for oarbureted air; a well open at its top within said reservoir, the top of said well being above the liquid level in the reservoir, there being restricted gravity liquid feeding means leading from the reservoir to the well; and means for bubbling gas to be carbureted at a rapid rate into said Well near the bottom thereof, the rate of supply of gas and liquid to the well being so proportioned that the gas flow displaces the major portion of the liquid over the top of the well and carburetion proceeds by bubbling of air in a shallow bath whose quantity is not materially affected by variation of the depth of liquid in the reservoir.

8. In a carburetor, the combination of a closed reservoir adapted to contain the entire charge of volatile liquid hydrocarbon to be evaporated, said reservoir having an offtake for carbureted air; a well open at its top within said reservoir, the top of said well being above the maximum liquid level in the reservoir, and said well having restricted liquid feeding means leading from the reservoir to the well; and means for discharging gas into the lower portion of the well at a rate which will displace from the well the major portion of the liquid hydrocarbon so that the effective bath of liquid hydrocarbon in the well is maintained by flow through said liquid feeding means and is approximately uniform.

9. In a carburetor, the combination of a closed reservoir adapted to contain the entire charge of volatile liquid hydrocarbon to be carbureted, said reservoir having an ofitake for carbureted air; a well open at its top within said reservoir, the top of said well being above the maximum liquid level in the reservoir and the bottom of the well being below the bottom of said reservoir, said well having restricted liquid feeding means leading from the lower portion of the reservoir to the well; and means for discharging gas into the lower portion of the well below the bottom of the reservoir at a rate which will displace from the well the major portion of the liquid hydrocarbon so that the efiective bath of liquid hydrocarbon in the well is maintained by flow through said liquid feeding means and is approximately uniform.

ELMO L. BROWN. 

